Hairdye preparation

Abstract

A hair dye composition comprising a component (A), which is a specified long-chain acyl sulfonic acid salt anionic surfactant, in an amount of 0.1 to 10.0 wt. %; a component (B), which is an aliphatic alcohol, in an amount of 0.25 to 25.0 wt. %; and a component (C), which is an acid dye and/or a natural dyestuff. The hair dye composition is stable even in a strongly acidic region (pH 1.5 to 4.5) where it exerts a dyeing effect. It has an appropriate viscosity and provides excellent sensation upon use. Furthermore, the composition can be easily rinsed off after use thereof.

1. A hair dye composition comprising a component (A), which is a long-chain acyl sulfonic acid salt anionic surfactant represented by the following formula (I):
   R 1 CO-a-(CH 2 ) n SO 3 M 1   (I), 
 
       wherein R 1 CO— represents a saturated or unsaturated fatty acid residue (acyl group) having an average carbon atom number of 10 to 22; a represents —O— or —NR—, wherein R represents a hydrogen atom or a C1–C3 alkyl group; M 1  represents a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium, or an organic amine; and n represents an integer of 1 to 3, in an amount of 0.1 to 10.0 wt. %; a component (B), which is an aliphatic alcohol, in an amount of 0.25 to 25.0 wt. %; a component (C), which is an acid dye and/or a natural dyestuff, and a component (D), which is an emulsion of non-volatile silicone. 
     
     
       2. The hair dye composition as recited in  claim 1 , further comprising benzyl alcohol and wherein the ratio by weight of the component (A) to the component (B) is 1:2.5 to 1:50. 
     
     
       3. The hair dye composition as recited in  claim 1 , wherein the component (C) is contained in an amount of 0.001 to 2.0 wt. %. 
     
     
       4. The hair dye composition as recited in  claim 1 , wherein the pH of the composition is 1.5 to 4.5.